Current speed: Slow water
Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.
This is our largest species of the genus. The sexes are alike in color, all brown, deepening to shining black on top of thorax and at both ends of abdomen, paler on appendages. Wings subhyaline with brown veins, and with a brown tint in the membrane at the roots. Costal cross veins numerous but weak as far as the stigmatic area where they are crowded; their tips strongly curved outward and often forked. Sometimes they anastomose forming a few small cells in an outer series next the costa. Vein Cu2 unattached at base. The forceps has a rounded basal lobe-like dilatation. The penes are separated by a broad U-shaped notch as wide as deep; the terminal orifice is guarded by a rounded inner lobe and an outer triangular tooth. The reflexed spur is short, lance-like or bladelike, and acute at the apex.